基于与HTPB相互作用共振光散射法测定Hg^(2+)

Determination of Hg^(2+) by Resonance Light Scattering Technique Based on the Interaction with HTPB

在酸性介质中,汞(Ⅱ)与过量溴离子反应生成四溴合汞(Ⅱ)阴离子,后者进一步与1-十六烷基三苯基溴化膦((1-Hexadecyl)triphenylphosphonium Bromide,HTPB)通过静电作用形成离子缔合体,引起体系的共振光散射信号显著增强,最大散射波长位于291.0 nm处,增强的散射信号强度与Hg2+浓度在0.04～1.5μmol/L范围内呈线性关系,检测限(3σ)为4.0 nmol/L.讨论了体系的最佳反应条件及外来物质的干扰,同时研究了体系的吸收光谱,并探讨了反应机理.建立的共振光散射法用于环境水样中Hg2+的测定,RSD≤4.42%.

In acidic medium, a resonance light scattering （RLS） analytical method of Hg（II） was established based on the enhanced RLS signal due to the interaction of （1-hexadecyl）triphenylphosphonium bromide （HTPB） and HgBr42-ion derived from the reaction between mercury ion and excess potassium bromide. The enhanced RLS intensity at 291.0 nm is proportional to the content of mercury（II） in a range of 0.04- 1.5 -tmol/L. The limit of detection （3a） is 4.0 nmol/L. In this work, the optimum reaction conditions and the interference of foreign substances of the system were investigated. At the same time, the absorption spectral as well as the reaction mechanism were also investigated. This method has been successfully applied to the determination of mercury（II） in environmental samples with RSD ≤4.42%.